On the morning of April 6, 1938, Jack Rebok, my assistant, selected one of the TFE cylinders that we had been using the previous day and set up the apparatus ready to go. When he opened the valve — to let the TFE gas flow under its own pressure from the cylinder — nothing happened. Jack called me over and asked whether we had used all the TFE from that cylinder. I said, I don't think so. We both tinkered with the valve a bit, and then thinking it might be stuck or closed in some way, we disconnected the cylinder from the line and pushed a wire through the valve opening. Still no TFE came out, although the weight of the cylinder showed that there was material inside. We were in a quandary. I couldn't think of anything else to do under the circumstances, so we unscrewed the valve from the cylinder. By this time it was pretty clear that there wasn't any gas left. I carefully tipped the cylinder upside down, and out came a whitish powder down onto the lab bench. We scraped around some with the wire inside the cylinder — or maybe I tapped it — I don't remember which — to get some more of the powder. What I got out that way certainly didn't, add up, so I knew there must be more, inside. Finally, more out of curiosity I suppose than anything else, we decided to cut open the cylinder. When we did, we found more of the powder packed onto the bottom and lower sides of the cylinder.